In spina bifida, the baby’s spine does not form correctly. In mild cases, permanent loss of some sensation or movement occurs. Severe cases include paralysis and varying degrees of loss of bowel and bladder control. Children born with spina bifida will undergo a lifetime of surgeries and face many health issues. Spina bifida cannot be cured. (The illustration below is courtesy of the US Centers for Disease Control and Prevention (CDC).

Another NTD is anencephaly in which the brain does not form properly. Pregnancies affected by anencephaly are often miscarried. Babies born with anencephaly die shortly after birth.

A rare NTD is encephalocele in which part of the brain protrudes through the skull.

Many NTDs can be prevented if women have 400 micrograms of folic acid daily at least one month before conception and in the early stages of pregnancy [1].

Fortifying flour and rice increases folic acid intake without requiring consumers to change their behaviors. One meta-analysis showed that fortifying wheat flour with folic acid reduced the incidence of NTDs by an average of 46%. [2]

A baby’s neural tube forms within the first four weeks of pregnancy. If women wait until they learn they are pregnant to take folic acid supplements, the baby’s neural tube may already be formed. Then it is too late for folic acid to have the protective effect.

The March of Dimes estimates that more than 300,000 babies are born with an NTD every year for a global birth prevalence of 24/10,000 [3]. Countries which track birth defects generally find that their NTD prevalence drops to less than 10 per 10,000 live births after they begin fortifying flour with folic acid [4].

Fortifying flour with folic acid is credited with preventing at least 35,500 of these birth defects a year or an average of 97 a day. Only about one-third of the world’s flour from industrial mills is fortified, however, so this is only 13% of the NTDs that might be prevented [5].

Some foods such as spinach and liver are rich in vitamin B9 which is called folate in unfortified foods. However, folate is not easily absorbed, making it "difficult for a woman to eat enough natural food folate to prevent neural tube defects" [6].

For example, to consume the recommended amount of food folate equivalents, a person would need to eat:

Some people have been told to avoid folic acid because they have a variation of the MTHFR (methyltetrahydrofolate reductase) enzyme. However, these individuals simply process folic acid more slowly than those without the variation. See the CDC recommendation for people with the MTHFR variation to continue taking folic acid.